Which of the following are boiler mountings and not boiler accessories? A. Pressure gauge B. Air preheater C. Superheater
A only
Understanding Boiler Mountings and Accessories
Boilers are equipped with various devices and components that ensure their safe operation and improve their performance and efficiency. These components are broadly classified into boiler mountings and boiler accessories.
What are Boiler Mountings?
Boiler mountings are essential fittings that are mandatory for the safe operation of a boiler. They are generally mounted directly onto the boiler shell and are necessary for controlling the steam and water flow, indicating crucial parameters, and ensuring safety under operating conditions. Without boiler mountings, the boiler cannot be operated safely.
Examples of boiler mountings include:
- Pressure Gauge: Indicates the internal pressure of the boiler.
- Water Level Indicator (Gauge Glass): Shows the water level inside the boiler.
- Safety Valve: Automatically releases steam when the pressure exceeds a safe limit.
- Stop Valve (Main Steam Valve): Controls the flow of steam from the boiler to the main steam pipe.
- Blow-off Valve: Used to drain water and remove sediments from the boiler.
- Feed Check Valve: Controls the flow of feed water into the boiler and prevents backflow.
- Fusible Plug: Melts at a specific high temperature to release steam and extinguish the furnace, preventing overheating if the water level drops too low.
What are Boiler Accessories?
Boiler accessories are devices installed to improve the efficiency and performance of the boiler. They are not strictly necessary for the safe operation of the boiler but help in conserving fuel, improving steam quality, or optimizing the combustion process. They are usually installed either within the boiler structure or externally as part of the boiler system.
Examples of boiler accessories include:
- Economiser: Heats the feed water using waste heat from flue gases.
- Superheater: Heats the saturated steam to a higher temperature (superheated steam).
- Air Preheater: Heats the combustion air using waste heat from flue gases.
- Feed Pump or Injector: Supplies feed water to the boiler against the boiler pressure.
Analyzing the Given Options
Let's classify the components listed in the question:
- Pressure gauge: As discussed, a pressure gauge is a mandatory safety device that indicates boiler pressure. It is a boiler mounting.
- Air preheater: An air preheater heats the combustion air using flue gases to improve efficiency. It is an accessory.
- Superheater: A superheater increases the temperature of saturated steam to improve thermal efficiency and reduce moisture content. It is an accessory.
The question asks which of the given options are boiler mountings and not boiler accessories.
- Option A (Pressure gauge) is a mounting. It is not an accessory. This fits the criteria.
- Option B (Air preheater) is an accessory. It is not a mounting. This does not fit the criteria.
- Option C (Superheater) is an accessory. It is not a mounting. This does not fit the criteria.
Therefore, only the Pressure gauge (A) is a boiler mounting and not a boiler accessory among the given options.
Based on this analysis, the correct answer includes only option A.
Important Questions from Boilers
A device which is used to drain off water from steam pipes without escape of steam is called
______ is NOT a water tube boiler.
Which of the following pipe joints would be suitable for pipes carrying steam?
Filling or decking in a cooling tower increases the rate of heat transfer by providing
The valves mounted on the boilers which change the direction of flow of steam by 90° and valves fitted in the pipelines which allow the steam in the same direction are respectively called as _____.
